/**
 * Copyright (C) 2002-2015   The FreeCol Team
 * <p>
 * This file is part of FreeCol.
 * <p>
 * FreeCol is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 * <p>
 * FreeCol is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.sf.freecol.common.model;

import javax.xml.stream.XMLStreamException;

import net.sf.freecol.common.i18n.Messages;
import net.sf.freecol.common.io.FreeColXMLReader;
import net.sf.freecol.common.io.FreeColXMLWriter;
import net.sf.freecol.common.util.Utils;


/**
 * A trade item consisting of some goods.
 */
public class GoodsTradeItem extends TradeItem
{

    /** The goods to change hands. */
    private Goods goods;


    /**
     * Creates a new <code>GoodsTradeItem</code> instance.
     *
     * @param game The enclosing <code>Game</code>.
     * @param source The source <code>Player</code>.
     * @param destination The destination <code>Player</code>.
     * @param goods The <code>Goods</code> to trade.
     */
    public GoodsTradeItem( Game game, Player source, Player destination,
                           Goods goods )
    {
        super( game, Messages.nameKey( "model.tradeItem.goods" ),
               source, destination );

        this.goods = goods;
    }

    /**
     * Creates a new <code>GoodsTradeItem</code> instance.
     *
     * @param game The enclosing <code>Game</code>.
     * @param xr The <code>FreeColXMLReader</code> to read from.
     */
    public GoodsTradeItem( Game game, FreeColXMLReader xr ) throws XMLStreamException
    {
        super( game, xr );
    }


    // Interface TradeItem

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isValid( )
    {
        return goods != null && goods.getType( ) != null
                && goods.getAmount( ) > 0
                && ( goods.getLocation( ) instanceof Ownable )
                && getSource( ).owns( ( Ownable ) goods.getLocation( ) );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isUnique( )
    {
        return false;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public StringTemplate getLabel( )
    {
        return goods.getLabel( true );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Goods getGoods( )
    {
        return goods;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setGoods( Goods goods )
    {
        this.goods = goods;
    }

    /**
     * {@inheritDoc}
     */
    public int evaluateFor( Player player )
    {
        final Market market = player.getMarket( );
        final Goods goods = getGoods( );
        int value;
        if ( ! isValid( ) )
        {
            return Integer.MIN_VALUE;
        }
        else if ( market == null )
        {
            value = 2 * goods.getAmount( );
            if ( getSource( ) == player ) value = - value;
        }
        else
        {
            if ( getSource( ) == player )
            {
                value = - market.getBidPrice( goods.getType( ), goods.getAmount( ) );
            }
            else
            {
                value = market.getSalePrice( goods.getType( ), goods.getAmount( ) );
                value = ( int ) Math.round( value
                                                    * ( 1.0 - player.getTax( ) / 100.0 ) );
            }
        }
        return value;
    }

    // Override Object

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean equals( Object other )
    {
        if ( other instanceof GoodsTradeItem )
        {
            return Utils.equals( this.goods, ( ( GoodsTradeItem ) other ).goods )
                    && super.equals( other );
        }
        return false;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int hashCode( )
    {
        int hash = super.hashCode( );
        return 37 * hash + Utils.hashCode( this.goods );
    }


    // Serialization

    /**
     * {@inheritDoc}
     */
    @Override
    protected void writeChildren( FreeColXMLWriter xw ) throws XMLStreamException
    {
        super.writeChildren( xw );

        goods.toXML( xw );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readChildren( FreeColXMLReader xr ) throws XMLStreamException
    {
        // Clear containers.
        goods = null;

        super.readChildren( xr );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readChild( FreeColXMLReader xr ) throws XMLStreamException
    {
        final Game game = getGame( );
        final String tag = xr.getLocalName( );

        if ( Goods.getXMLElementTagName( ).equals( tag ) )
        {
            goods = new Goods( game, xr );

        }
        else
        {
            super.readChild( xr );
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString( )
    {
        StringBuilder sb = new StringBuilder( 16 );
        sb.append( "[" ).append( getId( ) )
                .append( " " ).append( goods.getAmount( ) ).append( " " )
                .append( Messages.getName( goods ) ).append( "]" );
        return sb.toString( );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getXMLTagName( ) { return getXMLElementTagName( ); }

    /**
     * Gets the tag name of the root element representing this object.
     *
     * @return "goodsTradeItem".
     */
    public static String getXMLElementTagName( )
    {
        return "goodsTradeItem";
    }
}
